It is usually recommended that thatch be treated by mechanical thatching equipment, an operation usually referred to as scarification, but sometimes known as verticutting, although that term is also used for the process of cutting vertically into the turf using fine blades, sometimes known as turf grooming. It is recommended to carry out scarification in several treatments rather than attempting to remove all the thatch at once, but this is essentially because conventional scarifiers remove thatch in thin furrows, leaving ‘ridges’ of thatch between them, and so cannot remove all the thatch in one pass.
U.S. Pat. No. 6,094,860 discloses the use of artificial fibre reinforcement for grass turf areas in playing fields subject to heavy wear, and other patents and proprietary systems similarly involve the use of artificial fibre reinforcement.
“Desso® Grassmaster” is a turf reinforcement system in which artificial grass fibres are injected some 20 cm deep into a grass surface, projecting some 25 mm above the soil. The maintenance of this system, as regards mowing, verticutting and ventilating, is said to be no different from the maintenance of ordinary turf. Mowing, of course, must be carried out with the cutter height at or above the height of the artificial grass fibres, e.g. at 26 mm or more if the fibre height is 25 mm, otherwise they would be cut or pulled out.
The artificial grass fibres are injected into a matrix of sand, which of course has no nutritional value, and there is only a thin top layer of humus, if indeed any, so the natural grass needs to be treated with fertiliser more than it would if grown in deep soil. This exacerbates problems of disease and infestation, bearing in mind that about 97% of the turf is natural grass. The sand also, over the course of a playing season, compacts more than does the usual substrate of natural, unreinforced turf.
On this, or indeed any, turf, moreover, undesired grasses and weeds such as clover can be a problem. Clover is especially problematic on playing surfaces such as tennis courts, as it tends to be slippery. Weeds are usually treated with systemic herbicides, which take time to act and which may require several treatments over a space of weeks.